Question

The ice floats on water because:

• A. solids have lesser density than liquids
• B. it has open-cage like structure in which lesser molecules are packed per mL than water
• C. ice is lighter than water
• D. when ice is formed water molecules come closer and start floating.

Answer 1

Answer: (B)

it has open-cage like structure in which lesser molecules are packed per mL than water

in the solid state (ice), intermolecular interactions lead to a highly ordered but loose structure in which each oxygen atom is surrounded by $4$ hydrogen atoms; two of these hydrogen atoms are covalently bonded to the oxygen atom, and the two others (at longer distances) are hydrogen bonded to the oxygen atom’s unshared electron pairs.

this open structure of ice causes its density to be less than that of the liquid state, in which the ordered structure is partially broken down and the water molecules are (on average) closer together. When water freezes, a variety of structures are possible depending on the conditions. $9$ different forms of ice are known and can be interchanged by varying external pressure and temperature.